Cooking with sound: new stove/generator/refrigerator combo aimed at developing nations

A new device offers the hope of reliable refrigeration, heat for cooking, and …

Food preparation and storage can be a complex issue in the developing world with serious ramifications for public health. A consortium of universities and other organizations from the UK, US, and developing nations such as Bangladesh are coming together to tackle the problem by creating a single device that provides refrigeration, electricity, and heat for cooking.

The effort is part of the $4 million SCORE (Stove for Cooking, Refrigeration and Electricity) project aimed at finding more efficient and safe ways of utilizing biomass fuels such as wood. The University of Nottingham, University of Manchester, Imperial College London, and Queen Mary, University of London are the primary partners in the project, along with the Los Alamos Laboratories.

Malnutrition is one of the two main killers in the developing world, due in part to the difficulties in preparing and storing food. Refrigeration is all but impossible in areas where electrical service is absent or unreliable. Preparing food can also cause problems, especially with overuse of local resources. In Asia and Africa, much of the cooking is done over open fires and the resulting energy waste is estimated to be as high as 93 percent.

The consortium's device is based on thermoacoustic technology that has been under active development at Los Alamos Laboratories. Essentially, the device is a Stirling engine.

Device schematic

A wood-burning furnace is attached to a pipe that is shaped rather like a pulse jet engine. The heat from the stove drives a resonant wave in the tube, which also sucks heat out of the air at the other end. Hence, the stove has the ability to provide heat at one end of the tube and refrigeration at the other end. To generate electricity, a membrane is placed in the tube, which vibrates back and forth with the resonating gas; the project describes it as a "reverse loudspeaker." This can then be used to generate electricity.

A prototype device

In general, technology solutions do very little by themselves to help the poor, leading to the question of how much of a difference this device will make. Here, we have a well-targeted device that requires high technology to develop, but low technology to build and maintain. Provided that the appropriate local support and training can be put in place and the price kept low, the combination cooker-generator-refrigerator could prove useful.

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Chris Lee / Chris writes for Ars Technica's science section. A physicist by day and science writer by night, he specializes in quantum physics and optics. He lives and works in Eindhoven, the Netherlands.